In this blog post, we explored how using Markforged's Onyx material improves our 3D printed drone with its improved strength, stiffness, and surface finish.

Tuesday, August 9, 2016

Writer’s note: After a busy couple months, we’re resuming this series! Check out our first 3D printed arm here and our electrical system upgrades here. In this post, we’ll be discussing the advantages Onyx provides in creating more polished, stronger, and lighter drone arms than ever before!

We’re back with the third installment in the drone upgrade series! The IRIS+ drone that we’ve been retrofitting with Markforged parts has been coming along well. In the last post, we discussed the electrical modifications needed to fully customize the drone with 3D printed parts. After further customization of the drone, we decided to look back at the arms we printed in the first episode. While the Nylon/Carbon Fiber arms represented a vast improvement over the original injection molded parts, we felt we could further improve them by leveraging our new filament, Onyx, on the Mark Two.

From left to right, the original injection molded kit arms, the Nylon arms, and the Onyx. The Onyx arms are 13 grams lighter than the kit arms and 5 grams lighter than the Nylon arms.

Onyx is a little more dense than Nylon; however, it’s also much stiffer, meaning that we needed much less carbon fiber to properly reinforce it. The few carbon fiber isotropic fill layers give it plenty of strength while also cutting weight, making each of the new arms 5 grams lighter than their Nylon/Carbon Fiber counterpart. This increases the overall weight savings from 32g to 52g for all four arms without sacrificing strength.

Bottom view of the drone, showing the wire routing and the underside resolution of the Onyx prints.

Top view of the drone with Onyx arms.

Thanks to Onyx’s excellent surface finish, the complex features in the arms rivaled the quality and finish of the original injection molded arms. The wire tracks on the bottom of the arms (as seen on the bottom view of the 3D printed drone) printed flawlessly, with crisp edges and clean gaps. In addition, the motor vents (directly above the propellors in the same picture) have clear definition despite being a traditionally difficult feature to print. From the bottom, the new Onyx arms are virtually indistinguishable in resolution from the injection molded arms.

Close view of the kit (left) and Onyx (right) drone arms. Note the superstructure on the kit arms that isn’t needed on the Onyx arms.

Unlike the bottom, the top of the Onyx arms are quite different than the original injection molded ones. The strong internal structure of the Onyx arms eliminates the need for the large superstructure that dominates the top of the kit arms. As a result, the top of the Onyx arms are flat. The fully assembled 3D printed drone is more functional, lighter, and sleeker than the original model. We could talk more about the Onyx surface finish or the overall look, but the pictures speak for themselves.

Close view of the Onyx arms on the drone. Look at that surface finish!

The drone is re-assembled and ready to fly now! However, we have one more alteration that we want to experiment with before taking it for its maiden flight. Stay tuned for more on our 3D printed drone adventures!